| Year | 1939 |
| Date | 23-Feb |
| Volume | 80 |
| Issue | 1,972 |
| Page | 231 |
| Category | Electrical |
| Part | |
| Title | An Extemporised Intermittent Lighting Switch |
| Author | M.Odling |
| Notes | And Other Applications of the Syphonic Balance. Constructed from oddments, details of syphon tube and tank, adjustable constant water head, syphonic rocker adapted for rocking and washing photographs |